Dirk W. Grijpma
University of Twente, The Netherlands
Title: Poly(trimethylene carbonate) polymers and networks, Synthesis, properties and medical applications
Biography
Biography: Dirk W. Grijpma
Abstract
Poly(trimethylene carbonate) (PTMC) is an amorphous polymer with low glass transition, and is prepared by ring opening polymerization of the cyclic trimethylene carbonate (TMC) monomer. It can be copolymerized with other lactone monomers to yield materials with tuneable physical and chemical properties. Upon crosslinking flexible and elastic (co)polymer networks are obtained, with properties that resemble those of poly(dimethyl siloxane) (PDMS) rubber. Interestingly, the TMC monomer can be prepared from natural renewable resources using 1,3-propane diol that is obtained by fermentation of glucose.
While PTMC with number average molecular weights below 50000 g/mol are viscous or gummy materials with poor mechanical properties, high molecular weight linear PTMC is an amorphous, tough and flexible solid with a low glass transition temperature of -19 °C. The resistance to creep of the flexible polymer significantly increases when it is crosslinked. PTMC networks can be prepared by gamma-irradiation of linear high molecular weight PTMC polymer or by photo-crosslinking functionalized macromers based on TMC using UV-or visible light.
Materials based on PTMC are very useful in biomedical applications. Linear (co)polymers and (co)polymer networks prepared from TMC and D,L-lactide or ï¥-caprolactone were shown to be compatible with a large number of cells and implantation experiments in small animals showed only a mild tissue response. PTMC based polymers and networks were found to degrade in the body by an enzymatic surface erosion mechanism, without the release of acidic degradation products. This makes these polymers very well-suited as a matrix in the preparation of biodegrade composite materials for bone tissue engineering and drug delivery.
Here we will present work on the synthesis and properties of PTMC polymers and networks, their processing into medical implants by conventional processes and advanced additive manufacturing methods and their characteristics in the presence of cells and upon implantation.
Figure 1: Ring-opening polymerization of trimethylene carbonate (TMC) using stannous octoate (Sn(Oct)2) as catalyst to obtain high molecular weight poly(trimethylene carbonate) (PTMC).